1. Field of Invention
The present invention relates to a signal generation circuit and method, and more particularly to a circuit and method for generating the stochastic signal.
2. Description of Related Arts
Stochastic signals, as serial numbers, are widely used in various electronic products and play a very important role in the information security of the electronic products. At present, the serial numbers of the electronic products are generated by two methods. In the first method, the serial numbers are generated by the software. The serial numbers are provided by some randomized algorithms of the software. Therefore, the first method is adapted for the electronic products having the software operation, and it is prone to be cracked. In the second method, the serial numbers are generated by the hardware, namely, the internal integrated circuits. In generally, after finishing the integrated circuit manufacturing process, some branches of the internal circuits of the integrated circuits are fused at the high temperature or one-time programmable circuit programming is made for generating various serial numbers of the integrated circuits. The second method is performed after finishing the integrated circuit manufacturing process, so the cost of the integrated circuit is increased. Furthermore, it cannot ensure the uniqueness of the serial number among different integrated circuits. Also, the information security of the electronic products using the integrated circuits is decreased.